A publication that wants to publish an article about what it's like to have an abortion and therefore asks for submissions from women who have had an abortion is a specific example and is qualitatively different from a publication stating that they don't want articles from white people, fullstop.
I disagree. This publication wants to publish pieces about BAME experiences and so are only seeking submissions from those who have BAME experiences. That is in no way qualitatively different from only wanting to hear about abortion experiences from people who have had abortions.
but nowhere in your link does it show that this is a result of racial prejudice. Can you show this? I think it's more likely this is a result of the education system and the demographics going into certain fields.
This is a bit vague - if you're suggesting that our education system exhibits systematic racial bias which then affects the opportunities available to BAME people, then I broadly agree (albeit this is an overly simplistic analysis).
But if you're suggesting that BAME people have proportionately the exact same opportunities as white people and just choose not to take them up, then I don't agree and your position is not supported by evidence.
Consider for one thing the horrific racist abuse often faced by black journalists - Gal-Dem is a great (or rather, terrible) example of this. Look at the comments under their articles and you'll get a flavour for the kind of racist abuse BAME journalists face. Women journalists also experience this, particularly when discussing feminism, but without the added layer of racism.
Compare the treatment of Charlene White in choosing not to wear a poppy compared to Jon Snow when he made the same decision. Ask why she received death threats, threats of sexual violence and disgusting racist abuse where Snow did not.
Does that not already suggest that journalism is a more hostile environment for BAME people than white people, even before you did down into the statistics?
83% of journalists surveyed by NCTJ in 2016 indicated that they did work experience or internships before landing a paid role, and 95% of those were unpaid. Journalist Harrison Jones wrote in 2016 that the vast majority of these internships and placements come about through who you know, and contacts your parents have. This perpetuates a cycle - the vast majority of journalists are white, which means the vast majority of the young people they assist with internships are also white (not exclusively - but the majority) which means more young white people have opportunities to gain experience in journalism than young black people.
This lack of access is also tied heavily to class. 82% (again, research by NCTJ) of journalists have parents who are educated to degree level. This is hugely important given the emphasis on unpaid work experience - if you have parents who can financially support your unpaid work, you are in a better position. But the wage gap between BAME and white people educated to GCSE level is 11%, and 23% for university grads. 41% of Londoners in low income households are are BAME compared to their 35% share of the London population. So there are financial disadvantages faced by BAME people which makes accessing careers in journalism that much more difficult.